A user equipment (UE) may be configured to establish a connection to at least one of a plurality of different networks or types of networks to perform a variety of different functionalities via the network connection. For example, the UE may communicate with another UE through the network connection. In another example, the UE may communicate with various servers to exchange data.
A UE and a network may communicate over a particular bandwidth range. For instance, a UE may communicate with a network via a base station and the base station may be configured to provide a 20 MHz bandwidth range for communications. A bandwidth range may be referred to as a band and may be categorized as a wideband or a narrowband. A band may include a plurality of subbands. Wideband operations may utilize a larger band (e.g. 20 MHz, 10 MHz, etc.) compared to narrowband operations and, in some examples, the wideband may be equivalent to the entire bandwidth range available. Again, in some examples, narrowband operations may utilize a 1.4 MHz band. Depending on system conditions, there may be a plurality of narrowband regions defined within the available bandwidth range. Since wideband operations utilize a larger band compared to narrowband operations, wideband operations may transport more data than narrowband operations. However, utilizing a larger band correlates to an increase in the amount of power consumed by the UE. In contrast, utilizing a smaller band may conserve power but less data may be transported.
Certain devices may prefer to avoid the power cost of utilizing wideband operations and may elect to utilize narrowband operations. For example, in 3GPP Release 13, enhanced MTC (eMTC) or Category-M1 devices are introduced and may utilize a narrowband, in uplink and downlink communications, that has a range of 1.4 MHz (e.g. a six resource block (RB) narrowband).
After a UE has established a connection with the network, the UE may be instructed to provide Channel State Information (CSI) feedback to the network. CSI may indicate the quality of a communication channel between the UE and the network. A UE determines the CSI based on reference signals transmitted by a base station. The UE performs measurements on the reference signals and subsequently makes determinations to generate CSI feedback. The type of CSI feedback to be provided is typically determined by the network and may be categorized as periodic CSI feedback or aperiodic CSI feedback. Periodic CSI feedback may refer to a CSI report that is transmitted periodically with a specified time interval between transmissions. Aperiodic CSI feedback may refer to a CSI report that is triggered by a specific occurrence. CSI feedback may be used to determine subsequent scheduling for communications between the UE and the network.
When generating CSI feedback during narrowband operations, a UE may initially evaluate the CSI. In legacy approaches, CSI evaluation during narrowband operations may include 1) only evaluating the CSI over the scheduled narrowband or 2) evaluating the CSI of the entire bandwidth range available. Only evaluating CSI over the scheduled narrowband reduces radio frequency (RF) and computation power for the current CSI evaluation. However, it may jeopardize future power and performance because it may require more repetitions and retransmissions and the limited number of reference signals within the narrowband may degrade CSI feedback accuracy. On the other hand, evaluating the CSI of the entire band may significantly improve future power and performance at the cost of increasing power for the current CSI evaluation.